The bamM gene from Bacillus megaterium DSM319 encoding an extracellular beta-amylase was isolated and completely sequenced. Chromosomal inactivation by deletion mutagenesis resulted in total loss of amylolytic activity, indicative of a single starch-degrading enzyme. Functional characterization of the expressed protein revealed a maltogenic enzyme exhibiting optimal activities at pH 7.5 and 50 degrees C. Amylase expression is subject to catabolite repression by glucose. A putative cis-acting catabolite-responsive element (CRE) was identified; it is located within the bamM coding region, matching the position of the predicted signal peptide processing site. Base substitutions introduced by site-directed mutagenesis within the bamM-CRE--retaining unchanged the amino acid sequence--provoked a remarkable relief from carbon catabolite repression (CCR), thereby proving functionality of the CRE for CCR.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s002530100645 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Advances in fungal sugar transporters: unlocking the potential of second-generation bioethanol production.
Appl Microbiol Biotechnol
January 2025
Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil.
Second-generation (2G) bioethanol production, derived from lignocellulosic biomass, has emerged as a sustainable alternative to fossil fuels by addressing growing energy demands and environmental concerns. Fungal sugar transporters (STs) play a critical role in this process, enabling the uptake of monosaccharides such as glucose and xylose, which are released during the enzymatic hydrolysis of biomass. This mini-review explores recent advances in the structural and functional characterization of STs in filamentous fungi and yeasts, highlighting their roles in processes such as cellulase induction, carbon catabolite repression, and sugar signaling pathways.
View Article and Find Full Text PDFResistant for Biodegradation of Diesel Fuel at High Concentration and Low Temperature.
Microorganisms
December 2024
Department of Civil and Environmental Engineering, University of Strathclyde, James Weir Building, Level 5, 75 Montrose Street, Glasgow G11XJ, UK.
The resistance of 16 strains to diesel fuel was studied. The minimal inhibitory concentrations of diesel fuel against were 4.0-64.
View Article and Find Full Text PDFUpregulation of the gluconeogenesis pathway was observed by KDH1, mitigating glucose catabolite repression.
Food Sci Biotechnol
January 2025
Department of Bioengineering and Technology, Kangwon National University, Chuncheon, Republic of Korea.
Unlabelled: was engineered to mitigate carbon catabolite repression to efficient co-fermenting mixed sugars, which are primary components of cellulosic biomass. KDH1 produced ethanol with 0.42 ± 0.
View Article and Find Full Text PDFTransforming waste wood into pure L-(+)-lactic acid: Efficient use of mixed sugar media through cell-recycled continuous fermentation.
Bioresour Technol
December 2024
Leibniz Institute for Agricultural Engineering and Bioeconomy e. V. (ATB), Department Microbiome Biotechnology, Max-Eyth-Allee 100, Potsdam 14469, Germany. Electronic address:
Lignocellulosic media, containing diverse sugars and growth inhibitor compounds, pose great challenges to fermentation processes. This study tested thermophile Heyndrickxia coagulans strains for the production of L-(+)-lactic acid from waste wood hydrolysate. H.
View Article and Find Full Text PDFThe GATA factor AreB regulates nitrogen metabolism, fungal development, and aflatoxin production in Aspergillus flavus.
FEMS Microbiol Lett
January 2025
School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Article Synopsis
- Nitrogen is crucial for the growth and development of fungi, and while the GATA transcription factor AreA is well-studied, AreB’s role in Aspergillus flavus is less understood.
- Researchers characterized the areB gene in A. flavus, finding that its deletion negatively affects fungal growth, reduces spore production, and increases aflatoxin production, especially under poor nitrogen conditions.
- The study highlights areB's role as a negative regulator of nitrogen catabolite repression, affecting not only nitrogen utilization but also development and secondary metabolism, which could aid in managing aflatoxin contamination.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!